Automatic railway block-signal.



No. 746,582. PATENTED DEC. 8, 1903'.

' P. A. SAWYER.

AUTOMATIC RAILWAY'BLOOK SIGNAL.

APPLICATION FILED APR. 10. 1903.

N0 IODBL.

UNITED STATES Patented December 8, 1903.

PATENT OFFICE.

PICKENS AUGUSTUS SAWYER, OF MEMPHIS, TENNESSEE.

SPECIFICATION forming part of Letters Patent No. 746,582, dated December8, 1903.

Application filed April 10, 1903. Serial No. 152,007. (No model.)

arrangement of apparatus whereby a moving vehicle or train willautomatically and successively set danger-signals at predetermineddistances ahead of it and at the same time set cautionary and safetysignals behind it. I accomplish this by means of a series of-traokinstruments mechanically actuated by the train and connected by cableswith the signal-posts ahead of and behind it, all as hereinafter setforth, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a diagrammatic View of ablock-signaling systern embodying my invention. Fig. 2 is a longitudinalsection of the track instrument, on a large scale. Fig. 3 is across-section of the same. Fig. 4 is a vertical section of a signabpost.Fig. 5 is a side elevation ofthe same.

The railway is dividedinto any convenient number of blocks, and in eachblock is placed a track instrument which comprises a body having a top 1and upright sides or checks 2, between which are mounted to slidelongitudinally two racks 3 4, each having lateral ribs 5 to fit intoslots 6 in the cheeks. The two racks mesh with an intermediategear-wheel 7, so as to move simultaneously. The upper rack has teeth onits upper side, with which meshes a sector-gear 8'. The two gears arejournaled on pins 9, passing through the cheeks 2. The sector-gear isprovided with an upright lever 10, hinged to said gear and held inposition by a spring 11, so that it can yield when moved in onedirection, but will carry the sector-gear with it when moved in theother direction-say to the right in Fig. 2. This movement of the armwill cause the upper rack to slide to the left and the lower rack toslide to the right. The racks are kept normally in the position in whichthey are shown in Fig. 2 by means of a strong spring, preferably ahelical spring 12, abutting between the end of the upper rack and across-bar 13 at the end of the body.

On the locomotive or other vehicle is a tappet 14, projecting outsufficiently far beyond the track 15 to come in contact with the lever10 and actuate it when the locomotive is moving forward. If thelocomotive is running backward, the arm will merely yield when struck bythe tappet and the racks will not be actuated. V

The racks are connected by suitable cables with the signaling devices,which are carried on posts 16, set at suitable distances along the road.For convenience Ihave shown but one post between each pair of trackinstruments; but it will be understood that this number may be varied tosuit the requirements ofany particular system.

Each signaling device comprises two pivoted arms and two spring-catchesto hold them in a raisedposition, the arms dropping by their own Weightwhen released. The arms are pivoted at the upper end of. the post, andone of them, as 17, projectsto the left and the other, as 18, to theright. The arms may carry flags 19, if desired. The post is suitablyslotted to permit the movement of the arms in a vertical plane, thepivots 20 being located a short distance from the inner ends of thearms. The catches 21 stand above these short ends of the arms when thearms are raised and can be withdrawn by means of cables 22 23, runningup the sides of the post and over pulleys 24 to the ends of the catches.Springs 25 are attached to the post above the catches and are integralwith or attached to said catches at their inner ends, so as to form abeveled or cam surface where by the short inner ends of the arms maypress back the catches and pass by them when the arms are raised.Attached to the short end of the arm 17 is a cable 26, and a cable 27 issimilarly attached to the short end of the arm 18. The cable 26 runs tothe upper rack of the track instrument in the rear of the post, Whilethe cable 27 runs to the lower rack of the instrument in front of thepost. The cable 22 for actuating the catch for the arm 17 IOC is abranch of the cable 27, and the cable 23 for actuating the catch for thearm 18 runs to the second instrument ahead of the post.

The operation of my invention is as follows: When the tappet 14 strikesa lever 10 and rocks the sector-gear, the upper rack slides to the left(or backward with reference to the train) and pulls the cable 26, thusraising the arm 17 on the post ahead of the train, where it is caughtand held by the catch 21. At the same time the lower rack slides forward (to the right) and pulls both cables 23 and 27. Cable 27 raises thearm 18 on the post immediately behind the track instrument, and at thesame time its branch 22 trips the catch for the arm 17 on that post andlets it drop. Cable 23 simultaneously trips the catch for the arm 18 onthe second post inthe rear and lets that drop. Thus as the train passeseach track instrument it sets a danger-signal 17 on the post in frontand sets a cautionary signal 18 and drops the danger-signal on the firstpost in the rear and drops the cautionary signal on the second post inthe rear.

Having thus described my invention, what I claim is 1. In ablock-signaling system, the combination with a plurality of trackinstruments, of a plurality of block-signal posts, each carrying twosignaling-arms one for danger and the other for caution, a cableconnecting each track instrument with the danger-arm in the block infront of it, a cable connecting said instrument with the cautionary armin the block behind it, both of said cables operating to set saidsignal-arms and cable connections for tripping the danger-arms andcautionary arms in blocks behind said instrument.

2. In a block-signaling system, the combination with a plurality oftrack instruments, of a plurality of block-signal posts, signalarms onsaid posts, catches for holding said arms raised, and cables connectedwith each track instrument for simultaneously setting the danger-arm inthe block in front of said instrument, tripping the danger-signal in theblock behind said instrument, and setting the cautionary signal in saidblock, and tripping the cautionary signal in the second block behindsaid instrument.

3. In a block-signaling system, the combination with a plurality oftrack instruments, of a plurality of block-signal posts, signalarms onsaid posts, catches for holding said arms raised, a cable running fromeach track instrument to the danger-arm in the block in front, a secondcable running from said instrument to the cautionary arm in the blockbehind, a branch cable from said second cable to the catch for thedanger-arm in the block behind, and a third cable running from saidinstrument to the catch for the cautionary arm in the second blockbehind.

4. In a block-signaling system, a track instrument comprising twolongitudinally-sliding racks,an intermediate gear, a sector-gear meshingwith teeth on the upper rack, and a lever-arm hinged to saidsector-gear.

5. In a block-signaling system, a track instrument comprising a bodyhaving longitudinal slots in its sides, two racks having ribs fitted toslide in said slots, an intermediate gear meshing with said racks, andmeans for actuating the upper rack.

6. In a block-signaling system, a-track instrument comprising abody, tworacks fitted to slide longitudinally therein, an intermediate gearmeshing with. said racks, a sectorgear meshing with teeth on the upperside of the upper rack, a lever hinged to said sectorgear, a springattached to said arm and gear, and a spring between one of said racksand the end of said body.

7. In a block-signaling system, a signalpost having an arm pivotedthereto, a springcatch for retaining said arm in a raised position, acable attached to said arm, and a cable attached to said catch.

8. In a block-signaling system, a signalpost having two arms pivotedthereto, springcatches for holding said arms raised, and a cable forsimultaneously raising one arm and tripping the catch of the other arm.

9. In a block-signaling system, a signalpost having two arms pivotedthereto, a springcatch for each arm, a cable for raising each arm, abranch cable from one of said cables to the catch for the other arm, anda cable for the catch for the first arm.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

PICKENS AUGUSTUS SAWYER.

Witnesses:

J. O. COCKROFT, D. F. LIPFORD.

